Gems

Gems (Gemstones) are minerals which are especially beautiful and desired by the peoples of Arda. Many are crystalline and transparent, though some varieties are opaque. Most can be worked to accent their beauty.

The Ñoldor being masters of crafts and metallurgy had and a great horde of Gemstones many of which were stolen by Melkor after he left Aman.

Each of the Rings of Power was set with an identifying gemstone, but these are not specified. There are several alternate colors of sapphire, colored diamonds and other shades of beryl as well. Some opaque stones, such as jade and turquoise can be used as gemstones in jewelry.